Messages in this thread | | | Date | Wed, 17 Nov 2010 01:05:22 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 13/14] x86/ticketlock: add slowpath logic |
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On 11/17/2010 12:58 AM, Avi Kivity wrote: >> Actually in this case I'm pretty sure there's already a "set bit" >> function which will do the job. set_bit(), I guess, though it takes a >> bit number rather than a mask... >> > > > set_bit() operates on a long, while the intel manuals recommend > against operating on operands of different size, especially with > locked operations. I think newer processors have more relaxed > requirements, though.
Despite its prototype, set_bit() is pretty specifically using "orb" for a the constant case, or bts otherwise (I don't know what size memory operation bts is considered to generate).
J
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